This invention relates to an electrode boiler and to an insulator therefor. More particularly, this invention relates to an electrode boiler for producing steam or hot water.
Heretofore, various types of electrode boilers have been known for the production of steam or hot water. Generally, such electrode boilers are constructed with a vessel which is partly filled with water and which contains at least one electrode which can be connected to an alternating-current power supply in order to heat the water within the vessel. In addition, the electrode has been mounted within the vessel by means of an electrical insulator of ceramic material which is situated above the level of the water.
Generally, boilers of the above type have a counter electrode associated with the electrode and which is also electrically connected to the vessel. In such cases, water falling between the electrode and the counter electrode forms an electrical current path. However, during operation, it has been observed that substances contained in the water are carried by the steam that forms and/or by splashes of water into the insulator area and are deposited on the surface of the insulator in the form of crystals. As a result, a dangerous condition can be presented if the deposits coalesce to form electrically conductive layers which are liable to cause short circuits. Further, the deposits attack the ceramic insulator chemically so that the surface of the insulator progressively roughens so as to favor the creation of deposits and, thus, increase the risk of short circuits. In addition, the insulators are subjected to mechanical stresses which may lead to destruction of the insulators particularly since the ceramic insulators are made of brittle material. As a result, the insulators must be changed frequently causing undesirable interruptions in operation.
Accordingly, it is an object of the invention to reduce or completely eliminate the possibility of fracture of an insulator of an electrode boiler.
It is another object of the invention to increase the life of an insulator in an electrode boiler.